Liquid rinse cycle fabric conditioners have been used for many years to provide a softened feel to garments that have become harsh during the washing process. Most commercially available fabric conditioners use tallow based cationic actives, optionally in combination with nonionic actives, to deposit onto the garments to provide a soft tactile feel. In addition, fabric conditioners are well known to provide substantial fragrance benefits thus increasing their overall appeal to consumers.
Well known methods of providing both softening and fragrance benefits are described in the art. However, as consumer use habits and needs have changed over the years, the need to provide benefits in the areas of color care and fabric care have increased substantially. One highly desirable aspect of color care is the prevention of vagrant dyestuffs transferring from one garment to another during the course of the washing process. Various compositions which provide this benefit during the wash cycle are described in the prior art and available commercially in laundry detergent products. U.S. Pat. No. 5,458,809 (Fredj et al.) describes the use of a specific polymer type, PVP-N-Oxide, for use as a dye transfer inhibitor in the wash cycle. It is provided in a detergent mixture that contains anionic and nonionic surfactants and can include the use of mono long chain cationic surfactants. U.S. Pat. No. 4,954,292 (Hull et al.) describes the use of polyvinyl pyrrolidone to prevent redeposition of soils or dyestuffs when used in a laundry detergent in combination with an anionic surfactant and a specific nonionic with an HLB of 10.5 or less. U.S. Pat. No. 5,259,994 (Welch et al.) describes the use of polyvinyl pyrrolidone (PVP) in a particulate laundry detergent. The PVP is used in combination with hydrating salts and binding agents to form a separate particle which is then added to the remainder of the detergent which contains anionic and/or nonionic surfactants. EP 0508358A1 (Busch et al.) describes the use of cellulase enzymes and PVP in combination in a laundry detergent. The detergent may include anionic and nonionic surfactants and may optionally include mono long chain cationics. None of these cited publications specify the use of a dye transfer inhibitor in a rinse cycle product combined with the use of cationic surfactants to provide fabric softening benefits.
WO 95/05442 (Siklosi et al) describe the use of a specific molecule, PVP-N-Oxide, for use in a rinse conditioner application as an optional component that stabilizes cellulase enzymes. While this reference does cite the use of long chain cationic actives, it requires the presence of cellulase enzymes since the PVP-N-Oxide is utilized as an enzyme stabilizer.
U.S. Pat. No. 5,534,182 (Kirk et al) describes the use of dye transfer inhibitors in either the wash or rinse cycle of the laundry process. Dye transfer inhibitors cited include polyethoxylated urethane, acylamide polymer and certain poly(amino)acids. It fails to show the use of the specific dye transfer inhibitors cited in this application, nor does it mention the benefits of using any of the selected colorants described herein.
EP 0668902 B1 (Trinh et al) describes the use of dye transfer inhibitors such as PVP among others that are suitable for use in a liquid or sheet fabric softener. While it includes an extensive list of dye transfer inhibitors useful as rinse cycle products, and it states that dyes can be used in its compositions, Trinh et al fails to describe those dyestuffs cited in the present application which allow for successful use of the dye transfer inhibitors without incurring problems of staining or loss of color intensity.
U.S. Pat. No. 4,822,499 (Wahl et al) cites specific dyestuffs for use in rinse conditioners that provide a pink color and are light stable.
U.S. Pat. No. 4,844,820 (Piper) cites other specific dyestuffs for use in rinse conditioners that provide a pink color at low product pH (below 4).
U.S. Pat. No. 5,183,580 (Lew et al) cite specific dyestuffs for use in rinse conditioners that provide a green color.
U.S. Pat. No. 5,130,035 (Dell'Armo et al) describes specific dyestuffs for use in rinse conditioners that use red colorant to provide a stable pink product color.
U.S. Pat. No. 5,089,148 (van Blarcom et al) describes specific colorants for use in rinse conditioners that combine yellow and red colorant to provide a stable peach product color.
While the above mentioned patents cite some of the colorants for use in rinse conditioners that are included in the compositions of this invention, none of them cite the use of dye transfer inhibitors.
All of the cited publications fail to suggest the use of a dye transfer inhibitor such as PVP in combination with long chain cationic surfactants and specific colorants compatible with the dye transfer inhibitor for use in providing softening and other benefits in the rinse cycle without incurring increased potential for fabric staining. In part this results from the assumption that dye transfer inhibitors such as PVP are not able to provide additional benefits in this area to those already provided to some degree by the long chain cationic molecules themselves which are known to complex with some classes of anionic dyestuffs. It is the surprising finding that additional benefits in dye transfer inhibition are provided by the use of dye transfer inhibitors such as PVP when used in combination with long chain cationic surfactants and certain specified colorants in the rinse cycle, that provides a basis for our invention. This synergistic increase in dye transfer benefits during the rinse cycle when combined with the delivery of softening benefits from the long chain cationic surfactants and with no increase in fabric staining allows our invention to address two consumer valued needs that have to date been unavailable in a rinse cycle product. It is a further advantage that these benefits can be provided from a colored product that has a consumer pleasing appearance without having to incur an increased potential for fabric staining in use in the rinse cycle.